Network virtualization refers to structures and processes for combining computer hardware and computer software network resources and network functionality into a single, software-based administrative entity, sometimes referred to as a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization.
A hypervisor or virtual machine monitor (VMM) is a piece of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a host machine, and each virtual machine is called a guest machine.
A virtual local area network (VLAN) is a broadcast domain partitioned and isolated in a computer network at a data link layer, generally referred to as “layer 2” of the Open Systems Interconnection model (OSI model), a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology.
A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems. It generally includes redundant or backup power supplies, redundant data communications connections, environmental controls (e.g., air conditioning, fire suppression) and various security devices. Computers located in different data centers may find and communicate with each other via their media access control addresses (MAC addresses), unique identifiers assigned to network interfaces for communications at the data link layer of a network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and WiFi. Logically, MAC addresses are used in the media access control protocol sublayer of the OSI reference model.
Virtual Extensible LAN (VXLAN) is a network virtualization technology that uses a VLAN-like encapsulation technique to encapsulate MAC-based OSI layer 2 Ethernet frames within OSI layer 4 User Datagram Protocol (UDP) packets. VXLAN endpoints, which terminate VXLAN tunnels and may be both virtual or physical switch ports, are known as VXLAN tunnel endpoints (VTEPs). The VTEP is a host interface which forwards Ethernet frames from a virtual network via VXLAN, or vice-versa.
VXLAN is widely used as virtual network standard in cloud computing field to increase scalability to logical networks, and allows for layer 2 adjacencies across IP networks. Multicast or unicast with HER (Head-End Replication) is used to flood BUM (broadcast, unknown destination address, multicast) traffic. In computer networking, multicast (one-to-many or many-to-many distribution is a form of group communication where information is addressed to a group of destination computers simultaneously. Layer multicast enables a source to efficiently send to each member of a group in a single transmission, wherein copies are automatically created in other network elements, such as routers, switches, and cellular network base stations, but only to network segments that currently contain members of the group.
Network assisted multicast is generally implemented at the data link layer using one-to-many addressing and switching such as Ethernet multicast addressing, Asynchronous Transfer Mode (ATM) point-to-multipoint virtual circuits (P2MP) or Infiniband multicast. Network assisted multicast may also be implemented at the Internet layer using IP multicast. In IP multicast, the implementation of the multicast concept occurs at the IP routing level, where routers create optimal distribution paths for datagrams sent to a multicast destination address.